Acrylonitrile-butadiene-styrene copolymer (ABS) resins are prepared by dispersing a graft ABS copolymer (g-ABS) resin into a matrix polymer of a styrene-acrylonitrile copolymer (SAN) resin. The graft ABS copolymer (g-ABS) is a copolymer in which aromatic vinyl compounds (such as styrene monomers) and unsaturated nitrile-based compounds (such as acrylonitrile monomers) are grafted to a butadiene-based rubber polymer as central or core portion. Such ABS resins can have excellent properties, such as workability, impact resistance, strength, melt strength and the like, and also can have excellent coloring properties and gloss. Accordingly, ABS resins are widely used in various electric, electronic and miscellaneous components requiring an aesthetically pleasing external appearance.
However, ABS resins should also have resistance against strong chemicals such as acetic acid and industrial oils without cracking while maintaining excellent impact resistance when used in interior and exterior materials of electric and electronic appliances such as mixers, washing machines, electric fans, and the like. Such materials are subject to repetitive stresses due to the driving force of motors. Accordingly, such interior and exterior materials should be able to withstand the repetitive stresses for a predetermined length of time or longer without cracking or breaking.
SAN resins with a high acrylonitrile content in the ABS resins or acrylate-styrene-acrylonitrile copolymers in the ABS resins can be used to reinforce the chemical resistance of ABS resins. ABS resin and polyester resin can also be alloyed to reinforce chemical resistance of the ABS resins, such as disclosed in Korean Patent No. 159256. However, because polyester resin is a crystalline resin, the polyester resin may not be filled completely since the fluidity of the polyester resin is not good if the mold temperature is not set to a high temperature of at least 80° C. during injection molding. Further, when the structure of a mold is complicated, there can be problems with the molding of the polyester resin if the molding temperature is not sufficiently high (the polyester resin may only be partially molded).